Waha Milkvetch

Tium arthuri (M. E. Jones) Rydberg
Astragalus Arthuri M. E. Jones, Contr. W. Bot. 8: 20. 1898. Atelophragma Arthuri Rydb. Bull. Torrey Club 40: 51. 1913.
A perennial, with a cespitose caudex; stems 2-4 dm. high, slender, erect, sulcate and strigose; leaves 5-10 cm. long, erect; stipules deltoid, 2-3 mm. long; leaflets 21-29, oblong or elliptic, 6-10 mm. long, 2-3 mm. wide, glabrous above, sparingly pubescent beneath, obtuse; peduncles 1-1.5 dm. long, strict; racemes about 1 dm. long; bracts subulate, 2-3 mm. long; pedicels 3 mm. long, reflexed; calyx strigose with white and black hairs, the tube 4 mm. long, 2 mm. broad, the teeth lance-subulate, 3 mm. long; corolla white, about 12 mm. long; banner obovate, moderately arched; wings shorter, the blade oblong-oblanceolate, falcate; keelpetals shorter, the blade broadly lunate-obovate, more arched towards the apex ; pod strigose, stipitate, the stipe 7-8 mm. long, the body linear, gradually tapering at each end, 4-5 cm. long, 3-3.5 mm. wide and nearly as thick, the upper suture acute, the lower sulcate, the crosssection cordate, the septum nearly meeting the upper suture.
Type locality: Lake Waha, Idaho.
Distribution: Northern Idaho and eastern Washington and Oregon.

Perennial, Herbs, Stems woody below, or from woody crown or caudex, Taproot present, Nodules present, Stems very short, acaulescent or subacaulescent, Stems less than 1 m tall, Stems solid, Stems or young twigs sparsely to densely hairy, Leaves alternate, Leaves petiolate, Stipules conspicuous, Stipules membranous or chartaceous, Stipules persistent, Stipules free, Leaves compound, Leaves odd pinnate, Leaf or leaflet margins entire, Leaflets opposite, Leaflets 10-many, Leaves hairy on one or both surfaces, Inflorescences racemes, Inflorescence axillary, Inflorescence or flowers lax, declined or pendulous, Bracts very small, absent or caducous, Flowers zygomorphic, Calyx 5-lobed, Calyx glabrous, Petals separate, Corolla papilionaceous, Petals clawed, Petals white, Banner petal narrow or oblanceolate, Wing petals narrow, oblanceolate to oblong, Wing tips obtuse or rounded, Keel petals auriculate, spurred, or gibbous, Keel tips obtuse or rounded, not beaked, Stamens 9-10, Stamens diadelphous, 9 united, 1 free, Filaments glabrous, Style terete, Style persistent in fruit, Fruit a legume, Fruit stipitate, Fruit tardily or weakly dehiscent, Fruit elongate , straight, Fruit strongly curved, falcate, bent, or lunate, Fruit exserted from calyx, Fruit beaked, Fruit glabrous or glabrate, Fruit 11-many seeded, Seeds cordiform, mit-shaped, notched at one end, Seed surface smooth, Seeds olive, brown, or black.